Radial migration in galactic disks caused by resonance overlap of multiple patterns: Self-consistent simulations - Astrophysics > Astrophysics of GalaxiesReportar como inadecuado




Radial migration in galactic disks caused by resonance overlap of multiple patterns: Self-consistent simulations - Astrophysics > Astrophysics of Galaxies - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Abstract: We have recently identified a new radial migration mechanism resulting fromthe overlap of spiral and bar resonances in galactic disks. Here we confirm theefficiency of this mechanism in fully self-consistent, Tree-SPH simulations, aswell as high-resolution pure N-body simulations. In all barred cases we clearlyidentify the effect of spiral-bar resonance overlap by measuring a bimodalityin the changes of angular momentum in the disk, dL, whose maxima are near thebar-s corotation and outer Lindblad resonance. This contrasts with the smoothdistribution of dL for a simulation with no stable bar present, where strongradial migration is induced by multiple spirals. The presence of a disk gaseouscomponent appears to increase the rate of angular momentum exchange by about20%. The efficiency of this mechanism is such that galactic stellar disks canextend to over 10 scale-lengths within 1-3 Gyr in both Milky Way size andlow-mass galaxies circular velocity ~100 km-s. We also show that metallicitygradients can flatten in less than 1 Gyr rendering mixing in barred galaxies anorder of magnitude more efficient than previously thought.



Autor: I. Minchev, B. Famaey, F. Combes, P. Di Matteo, M. Mouhcine, H. Wozniak

Fuente: https://arxiv.org/







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